Approximately 11 lysosomal enzymes are known to be involved in the degradation of mucopolysaccharides. The absence of any one of these enzymes results in the accumulation of incompletely degraded glycosaminoglycans and a corresponding and specific genetic disease. A new sulfatase, which hydrolyzes a linkage found in highly sulfated mucopolysaccharides such as heparin has been found in human urine and partially purified. Its absence may lead to an as yet unidentified mucopolysaccharidosis.